Unsaturated organi-tin mercaptides, their preparation and use

ABSTRACT

Unsaturated organo-tin mercaptides, useful as stabilisers for halogenated vinyl resins, are obtained by reacting x mols of a mercaptocarboxylic acid HSXCOOH with y1 mols of an alcohol HOYOH or mixture thereof with y2 mols of alcohol HOY&#39;&#39;OH and/or y3 mols of alcohol ROH, where X is C1 4 alkylene or phenylene, Y is C1 10 alkylene or cycloaliphatic of five or six ring carbons, each with ethylenic and/or acetylenic bonds but not more than two of each type of bonds, Y&#39;&#39; is C1 10 alkylene or cycloalkylene with five or six ring carbons, R is C1 8 alkyl or alkenyl, cycloalkyl or cycloalkenyl with five or six ring carbons, or phenyl (C1 4) alkyl, with x, y1, y2 and y3 having specified interrelationships, to form an intermediate, and reacting the intermediate with a tin component, which is z1 mols of diorgano tin derivative R1 R2 SnO or R1 R2 SnCl2, or mixture thereof with z2 mols of mono-organo tin derivative which is a stannoic acid monomer or polymer (R1SnO1.5), R1SnCl3, R1Sn(OH)Cl2 or R1SN(OH)2Cl where R1 and R2 are C1 10 alkyl and x, z1 and z2 have specified interrelationships.

United States Patent [191 Bakassian [4 June 18, 1974 UNSATURATED ORGANl-TIN MERCAPTIDES, THEIR PREPARATION AND USE [75] Inventor: Georges Bakassian,

Apr. 12, 1972 France 72.12771 Mar. 14, 1973 France 73.9097

[521' US. Cl. 260/429.7, 260/45.75 K [51] Int. Cl. C07i 7/22 [58] Field of Search 260/4297 [56] References Cited UNITED STATES PATENTS 2,830,067 4/1958 Ramsden 260/4297 3,293,273 12/1966 Gloskey 260/4297 3,525,761 8/1970 Seki et al. 260/4297 3,642,846 2/1972 Hoch 260/4297 3,669,995 6/1972 Fath et a1 260/4297 Primary Examiner-Daniel E. Wyman Assistant ExaminerA. P. Demers Attorney, Agent, or Firm-Stevens, Davis, Miller & Mosher ABSTRACT Unsaturated organo-tin mercaptides, useful as stabilisers for halogenated vinyl resins, are obtained by reacting x mols of a mercaptocarboxylic acid HSXCOOH with y mols of an alcohol HOYOH or mixture thereof with y mols of alcohol HOYOH and/or y mols of alcohol ROI-1, where X is C alkylene or phenylene, Y is C alkylene or cycloaliphatic of five or six ring carbons, each with ethylenic and/or acetylenic bonds but not more than two of each type of bonds, Y is C alkylene or cycloalkylene with five or six ring carbons, R is C alkyl or alkenyl, cycloalkyl or cycloalkenyl with five or six ring carbons, or phenyl (C alkyl, with x, y,, y and y having specified inter-relationships, to form an intermediate, and reacting the intermediate with a tin component, which is 2 mols of diorgano tin derivative R, R SnO or R R SnCI or mixture thereof with 2 mols of mono-organo tin derivative which is a stannoic acid monomer or polymer (R SnO1.5), R SnCl R,Sn(Ol-1)Cl or R,SN(OH) Cl where R and R are C alkyl and x, 21 and Z2 have specified interrelationships.

9 eisi'nsnonEWng? 7 UNSATURATED ORGANI-TIN IVERCAPTIDES,

THEIR PREPARATION AND USE This invention relates to organo-tin mercaptides which are particularly suitable for stabilising chlorinated vinyl resins.

It is known from French Pat. Nos. 1,055,906, 1,085,807 and 1,138,451 that diorgano-tin mercaptides are good stabilisers for chlorinated vinyl resins, and especially for polyvinyl chloride. It has been recommended to use, in particular, saturated mercaptides such as dibutyl-tin or dioctyl-tin bis-(isooctylmercaptoacetate), these mercaptides currently forming the most effective stabilisers. However, these compounds are not completely satisfactory in some of their uses. Thus they do not prevent the appearance of a yellow colouration in the manufacture of transparent thin walled objects by high temperature extrusion. It is known that such a technique of extrusion will give high productivity only if the chlorinated vinyl resin compositions are heated to temperatures of 180 to 230C for short periods (e.g. 2 to 5 minutes).

The present invention provides a process for the preparation of an unsaturated organo-tin mercaptide which comprises in step (a) reacting, to form an intermediate x mols of a mercaptocarboxylic acid of the formula:

HS X COOH with a hydroxylic component, which is y, mols of a compound of the formula HO--YOH or a mixture thereof with at least one of y mols of a compound of formula HOY'--Ol-l and y mols of a compound of formula ROH, wherein X represents a straight or branched chain alkylene group of one to four carbon atoms, or a phenylene group,

Y represents a straight or branched chain, aliphatic,

divalent hydrocarbon radical with at most 10 carbon atoms, or a cycloaliphatic radical with five or six ring carbon atoms, the radical Y being divalent with at least one of an ethylenic and acetylenic bond and a maximum of two ethylenic and two acetylenic bonds,

Y represents an alkylene group with one to 10 carbon atoms, or a cycloalkylene group with five or six ring carbon atoms, R represents a straight or branched chain alkyl or alkenyl radical with at most eight carbon atoms, a cycloalkyl or cycloalkenyl radical with five or six ring carbon atoms, or a phenylalkyl group, the alkyl substituent of which contains one to four carbon atoms, and x, y y and y are subject to the following inequalities:

and in step b) reacting the intermediate with a tin component, which is:

2, mols of a diorgano-tin derivative of formula R R SnO or R,R,snc1 or a mixture of 2, mols of the diorgano-tin derivative with 22 mols of a monoorgano-tin derivative, which is a stannoic acid monomer or a polymer thereof with recurring units of formula R SnO or of formula each of R and R which are the same or different. represents a straight or branched chain alkyl group with one to 10 carbon atoms, and x, z; and 2 are subject to the following inequalities:

The organo-tin mercaptides produced according to the general process which has just been defined, have a complex structure and can contain in particular the following groups:

Ll. J

Usually the mercaptide contains one to five of such groups it being possible in particular for the latter to be bonded in such a way as to form monomeric, dimeric or oligomeric compounds. By way of illustration, the monomeric and dimeric forms have been represented as follows:

dimeric form In the process of the invention an unsaturated diol HO-Y-OH and a diorgano-tin compound are reacted together. The use of each of the following reagents is optional, a saturated diol, a saturated or unsaturated monoalcohol and a monoorgano-tin derivative, each of the formula given above. Based on the general process, it is thus possible to define various processes for producing the mercaptides which are of different degrees of simplicity according to whether only one of the two reagents, the unsaturated diol or the diorgano-tin derivative, is partially replaced. The most complex process is that in which all the possible different variables are involved simultaneously. As is apparent from the above inequalities, the replacement of a part of the unsaturated diol is such that the proportion of hydroxyl groups provided by the saturated diol and/or the monoalcohol is at most equal to 50 percent of the overall sum of the hydroxyl groups present in the hydroxylic component. Furthermore, the tin-mercapto-ester group bonds (involving the sulphur atom) provided by the monoorgano-tin derivative form at most 25 percent of all the tin-mercapto-ester group bonds formed from the diorgano-tin derivative and the monoorgano-tin derivative.

The compound which results from step (a) of the process, is an unstable compound which changes easily into a resinous substance. It is thus recommended not to attempt to isolate it, and to use it rapidly, as it is, for step (b). When y y and Z2 are 0, and z, and y, are 0.5n, then this intermediate compound comprises in particular the a, w-dimercaptodiester of the formula:

optionally combined with a small proportion of secondary products of the formula:

It is recommended that the process according to the invention be carried out in a solvent which is not miscible with water, such as, for example, aliphatic, cycloaliphatic or aromatic hydrocarbons such as hexane, cyclohexane, petroleum ether, methylcyclohexane, benzene or toluene. The water formed during the reaction is advantageously removed e.g. by azeotropic distillation. In order to assist the esterification reaction of step (a), it is possible to add any known esterification catalyst, for example an acid such as p-toluene-sulphonic acid or sulphuric acid. The conversion into a tin mercaptide is advantageously carried out by employing a dialkyl-tin oxide e.g. di-n-butyl or di-n-octyl-tin oxide, preferably with removal of water e.g. by azeotropic distillation. When a dichlorodialkyistannane is used, it is preferable simultaneously to introduce an agent for neutralising the hydrochloric acid liberated (e.g. ammonia or an amine).

Examples of the unsaturated diols, which can be used and which preferably have one or two ethylene bonds or one acetylene bond, are Z-butene-l ,4-diol, 2- pentene-l,5-diol, hexene-l,6-diol, ctene-l,8-diol, lbutene-3,4-diol, l-pentene-3,4-diol, 2-pentene-l,4- diol, Z-hexene- 1,5-diol, 3-heptene-6,7-diol, 4-octene- 3,6-diol, Z-butyne-l ,4-diol, 2-pentyne-l,4-diol, 3 hexyne-2,5-diol, l,5-hexadiene-3,4-diol, 4-octyne-3,6- diol, 2,6-octadiene-4,5-diol and 3-methyl-2,6-heptadiene-4,5-diol. Preferably 2-butene-l,4-diol is advantageous.

Examples of the mercaptocarboxylic acids are thioglycollic acid, B-mercaptopropionic acid, y-mercaptobutyric acid, fi-mercaptovaleric acid, thiolactic acid, thiosalicylic acid, aand B- mercaptobutyric acids and B- and y-mercaptovaleric acids.

Examples of the saturated or unsaturated monoalcohols are isobutanol, n-butanol, isooctanol, octanol, cyclopentanol, cyclohexanol and phenylethyl alcohol. Preferably isobutanol, n-butanol, isooctanol, octanol are advantageous.

The unsaturated mercaptides prepared by the process of the invention can be used, after removal of the solvent, for stabilising halogenated vinyl resins and the present invention comprises compositions comprising such a resin and at least one of the unsaturated mercaptides. They are generally introduced into the resin to the extent of 0.2 to 3 percent by weight relative to the weight of resin. By halogenated vinyl resins there are to be understood, in accordance with terminology which is well known to those skilled in the art, polyvinyl chloride and its copolymers in which the part originating from vinyl chloride predominates. Examples of the compounds, which are suitable for copolymerisation with vinyl chloride, are vinyl esters such as vinyl acetate, vinyl bromide, vinyl fluoride and vinyl butyrate, vinyl ethers such as vinyl ethyl ether, acrylic acid and its derivatives such as ethyl acrylate, ethyl methacryl ate, acrylonitrile, methacrylonitrile and acrylamide, allyl compounds such as allyl chloride and allyl acetate, and ethylenic compounds such as ethylene, propylene and butadiene.

The halogenated vinyl resin may be mixed with other polymers e.g. a styrene/butadiene/methyl methacrylate terpolymer for improving the impact resistance of the composition.

The mercaptides according to the invention have a greater retarding effect on yellowing than that of their saturated homologues. These mercaptides are thus very particularly suitable for producing thin films or transparent objects by extrusion or calendering techniques.

The Examples which follow illustrate the invention.

EXAMPLE 1 44 g of 2-butene-l,4-diol are introduced slowly, over the course of 2 hours 30 minutes, into a flask containing 97 g of thioglycollic acid, 600 ml of toluene and l g of paratoluenesulphonic acid, the mixture having been brought to the reflux temperature (1 12C The water formed is removed completely by azeotropic distillation. When the esterification is complete, g of di-(n-octyl)-tin oxide are added and the mixture is heated under reflux for 2 hours l5 minutes, with removal of the water formed during the reaction by azeotropic distillation. The toluene is finally removed by distillation and 235 g of organo-tin mercaptide are obtained, the identification of which was carried out in particular by IR. spectrometry. The product consists essentially of groups of the formula:

its average molecular weight is 1,085 (by ebulliometry in benzene).

This compound contains small proportions of groups of the formula;

(approximately 10 to 20 percent; determination by infra-red analysis).

EXAMPLE 2 53 g of B-mercaptopropionic acid and 22 g of 2- butene-l,4-diol are reacted, in benzene, in accordance with the procedure of the preceding Example, and the reaction is continued until the water formed has been completely removed. 62 g of di-(n-butyl)-tin oxide are then added and the reaction is continued as in Example 1. l20 g of organo-tin mercaptide consisting essentially of groups of the fomiula:

are thus obtained.

This compound contains small proportions of groups of the formula:

I1C4HO I (approximately to percent; determination by in fra-red analysis).

EXAMPLE 3 2i .5 g of Z-butyne-l ,4-diol and 250 ml of toluene are introduced into a flask and heated to the reflux temperature (l 10C), and a mixture containing 48 g of thioglycollic acid and 0.5 g of p-toluenesulphonic acid is run in slowly over the course of 1 hour. The water formed during the reaction is removed by azeotropic distillation, and then 62 g of dibutyltin oxide are added and the mixture is heated under reflux for 45 minutes, removing the water formed by azeotropic distillation. After distillation of the toluene, 111 g of organo-tin mercaptide, consisting essentially of groups of the formula:

6 EXAMPLE 5 Various samples based on polyvinyl chloride resin, having the following composition, are prepared:

Commercial polyvinyl chloride, sold commercially 100 g under the tradename LUCOVYL BB 800 Styrcnc/butadiene/mcthyl methacrylate terpolymer, 10 g used as an additive to increase impact resistance l,3-Butylene glycol ester of oxidised lignite wax, sold 1 g commercially under the tradename Wax E Stabiliser (diorgano-tin mercaptide) l g One of the following stabilisers is used for each mixture:

Stabiliser A That prepared in Example I Stabiliser B That prepared in Example 2. Stabiliser C Prepared according to Example l.

replacing butenediol by l,4-butanediol.

Each mixture is melted in a two-roll revolving at a speed of 15 revolutions/minute and heated to 180C (temperature maintained to within about 2C). Sam- Duration of Stabilised PVC resin heating at Stabillser A Stabiliser B Stabiliser C l0C in (Example 1) that of Example 2 (saturatedhomologue minutes of stabilisa A) appearance GARDNER appearance GARDNER appearance GARDNER number number number 5 Colourless 0 Colourless 0 Pale yellow 0 8 Colourless 0 Colourless 0 Light yellow l l l Colourless 0 Colourless 0 Yellow increasing intensity 2 l4 Colourless 9 Colou rless 0 Yellow do. 2 l7 Pale yellow 0.5 Pale yellow 0.5 Yellow do. 3 2O Pale yellow 0.5: 0.5 Yellow 4 Light yellow are obtained.

EXAMPLE 4 are o'sxaiaea These experiments show that the unsaturated organo-tin mercaptides have a greater heat stabilising effect than the effect produced by the saturated homologues.

EXAMPLE 6 I Two stabilised polyvinyl chloride resin compositions are used as in Example 5 but with stabilisers A-C replaced by l g of the stabiliser of Example 3 in composition and l g of the stabiliser of Example 4 in other composition.

Each mixture is melted in a two-roll mill, revolving at a speed of 15 revolutions/minute and heated to lC. (temperature maintained to within about 2C). Samples are removed, the first after being worked for 5 minutes on the calenders and the following samples.

every 3 minutes thereafter, and the colourations are noted (visual examination). The results are given in the following table:

I claim:

1. Process for the preparation of an unsaturated organo-tin mercaptide which comprises in step (a) reacting, to form an intermediate, 1: mols of a mercaptocarboxylic acid of the formula:

HS X COOl-l with a hydroxylic component, which is y, mols of a compound of the formula l-lO-Y-OH or a mixture thereof with at least one of y mols of a compound of formula HOY--OH and y mols of a compound of formula ROH,

wherein X represents a straight or branched chain alkylene group of one to four carbon atoms, or a phenylene group, Y represents a straight or branched chain, aliphatic, divalent hydrocarbon radical with at most carbon atoms, or a cycloaliphatic radical with five or six ring carbon atoms, the radical Y being divalent with at least one of an ethylenic and acetylenic bond and a maximum of two ethylenic and two acetylenic bonds,

Y represents an alkylene group with one to 10 carbon atoms, or a cycloalkylene group with five or six ring carbon atoms, R represents a straight or branched chain alkyl or alkenyl radical with at most eight carbon atoms, a cycloalkyl or cycloalkenyl radical with five or six ring carbon atoms, or a phenylalkyl group, the alkyl substituent of which contains one to four carbon atoms, and x, y,, 32 and y are subject to the following inequalities:

and in step (b) reacting the intermediate with a tin component, which is 1, mols of a diorgano-tin deriva tive of formula R R SnO or R R snCl or a mixture of z, mols of the diorgano-tin derivative with 2 mols of a monoorgano-tin derivative, which is a stannoic acid monomer or a polymer thereof with recurring units of formula R,SnO or of formula R SnCl R,Sn(OH)C1 or R,Sn(OH) Cl, wherein each of R, and R which are the same or different, represents a straight or branched chain alkyi group with one to 10 carbon atoms, and x, z, and Z are subject to the following inequalities:

2. A process according to claim 1 wherein Z2 is 0.

3. A process according to claim I wherein y is 0.

4. A process according to claim I, wherein y is 0v 5. A process according to claim 1, wherein Y contains one ethylenic or acetylenic bond.

6. A process according to ciaim 1 wherein at least one of steps (a) and (b) are carried out with azeotropic removal of water.

7. A process according to claim 1 wherein step (a) is carried out in the presence of an acid catalyst.

8. A process according to claim 1 wherein step (b) is carried out in the presence of a hydrogen chloride acceptor when the tin component contains chlorine.

9. A process according to claim 1 which comprises in step (a) reacting a mercaptocarboxylic acid, which is thioglycollic or B-mercaptopropionic acid, with a hydroxylic component, which is Z-butyne-l ,4-diol, 2- butene-l,4-diol of a mixture of 2-butene-L4-diol and isobutanol, in the presence of p-toluenesulphonic acid to form an intermediate, and in step (b) reacting the intermediate with a tin component which is di-(nbutyl) tin oxide or di-(n-octyl) tin oxide.

l I 4 i 

2. A process according to claim 1 wherein z2 is
 0. 3. A process according to claim 1 wherein y2 is
 0. 4. A process according to claim 1, wherein y3 is
 0. 5. A process according to claim 1, wherein Y contains one ethylenic or acetylenic bond.
 6. A process according to claim 1 wherein at least one of steps (a) and (b) are carried out with azeotropic removal of water.
 7. A process according to claim 1 wherein step (a) is carried out in the presence of an acid catalyst.
 8. A process according to claim 1 wherein step (b) is carried out in the presence of a hydrogen chloride acceptor when the tin component contains chlorine.
 9. A process according to claim 1 which comprises in step (a) reacting a mercaptocarboxylic acid, which is thioglycollic or Beta -mercaptopropionic acid, with a hydroxylic component, which is 2-butyne-1,4-diol, 2-butene-1,4-diol of a mixture of 2-butene-1,4-diol and isobutanol, in the presence of p-toluenesulphonic acid to form an intermediate, and in step (b) reacting the intermediate with a tin component which is di-(n-butyl) tin oxide or di-(n-octyl) tin oxide. 